Business forms which can be folded, including forms which can be folded for mailing, have been developed to employ pressure-sensitive adhesive to maintain each form in a folded, sealed closed condition. For example, a pressure seal C-fold mailer business form is disclosed in U.S. Pat. No. 5,201,464. As used herein, the terms "business form" and "form" include a variety of sheets or documents that may or may not bear printed indicia.
Various apparatus have been developed for applying pressure to such folded forms to "activate" the adhesive and cause the folded sheet portions of the business form to stick together. One such apparatus is sometimes described as a "pressure sealer," and typically employs cooperating pairs of rollers through which the folded business form is fed. Examples of such apparatus are disclosed in U.S. Pat. Nos. 5,133,828, 5,183,527, 5,656,118, and 5,772,841.
Pressure sealer apparatus can be designed to accommodate a folded business form having a specific thickness in the as-folded condition. The apparatus may employ an adjustment mechanism for adjustably setting the apparatus to handle business forms of varying thicknesses in the as-folded condition.
Nevertheless, the operator of the apparatus may inadvertently feed into the apparatus a business form that is thicker than the type for which the apparatus has been designed or set. Also, two or more folded business forms may be inadvertently fed together, one on top of the other into the apparatus. In either case, the increased thickness of the form or forms in the apparatus may cause the apparatus to "jam" and stop feeding the form or forms through the apparatus.
The apparatus motor does not have enough power to feed the thicker form or forms through the apparatus, and the motor may "stall," and/or a control circuit in the apparatus may effect termination of the motor operation, until the thicker form or forms are manually removed.
It may be difficult to release a jammed form or forms because such apparatus typically employs spring-biased rollers to apply relatively high pressure to the forms, and the high forces imposed on the apparatus components and forms must be accommodated during normal operation and must also be overcome during special "jam-clearing" operations.
It would be desirable to provide an improved system for accommodating release or removal of a form or forms that have become jammed in the apparatus.
Preferably, such an improved system should permit release of the form or forms without requiring disassembly of portions of the apparatus.
Further, such a system should be simple to operate and should be relatively inexpensive to manufacture and incorporate in the apparatus.
It would also be desirable if such a system could be employed in a pressure sealer apparatus that is part of an overall combination machine that could include an upstream sheet folder apparatus which may have a pair of rollers that could also function as part of the pressure sealer apparatus.
It would also be desirable to provide an improved system which could accommodate different sheet thicknesses as well as a different number of folds of such a sheet.
Additionally, it would be beneficial if such a system could be incorporated in apparatus that is relatively small. In particular, it would be advantageous to provide the system with a configuration and size that could be accommodated in a relatively small, table-top machine for use on an office desk or table.
The present invention provides an improved roller system for use in a pressure sealer which can accommodate designs having the above-discussed benefits and features.